This invention relates to methods and apparatus for processing material, and more particularly to a method and apparatus for processing sugarcane in which sugarcane stalk material is separated into component parts.
Sugarcane stalk consists of an outer epidermis material, an intermediate fibrous material called rind, and a central pulpous material called pith. Significantly, the pith and rind components of the sugarcane each contain sugar juices as well as other valuable substances, including fibrous materials.
It has been recognized that increased utilization may be made of sugarcane stalk material if at least the pith and rind components thereof are individually separated from each other prior to extraction of the sugarcane juices, rather than subjecting the stalk material to a conventional whole cane milling treatment which crushes the whole stalks to a point where all the stalk components are intermingled such that the juice is contaminated and the rind has lost much of its integral fibrous structure.
Through such separation, the pith component of the sugarcane may be individually processed to obtain sugar juices and various other fibrous and non-fibrous components. The rind portion, with its fibrous structure still substantially intact, can be treated for the extraction of sugar juices as well as other materials such as, for example, lignin, natural resins, and certain minerals. The rind can then be dried and used in making certain commodities such as paper and pressboard. If desired, the epidermis portions may be removed from the rind and treated to recover wax and other components.
A distinct discovery in the art for accomplishing an effective separation of stalk components was provided by Robert B. Miller who recognized that disintegration of sugarcane as proposed, for example, by U.S. Pat. No. 1,040,559, and as is involved in conventional whole stalk crushing, is not the answer to effective pith and rind separation. Miller proposed the splitting of sugarcane stalk, followed by scooping or brushing pith from the stalk halves without substantially disturbing the fiber structure of the rind. The Miller contribution and technique is disclosed, for example, in U.S. Pat. Nos. 3,424,611, and 3,464,877, referred to above. The major breakthrough in sugarcane processing technology provided by Miller opened the door to the development of improved commercial facilities for handling sugarcane stalk and separating its components.
A significant advance in the sugarcane component separation art has been contributed by the present inventor who proposed a systematic technique for rapidly handling large quantities of sugarcane stalk material in which the stalk components are effectively separated. In one aspect of this technique a channeled chute is utilized for guiding a flow of stalk material to a resilient feed roll assembly. The resilient feed roll assembly is arranged to yieldably grip opposite sides of sugarcane stalks and feed the stalks against a slitting blade. The particular arrangement of the feed rolls and slitting blade, as well as the use of a yieldable gripping assembly, enables a large number of stalks to be simultaneously fed and opened-up at a high rate. The opened-up stalk halves each pass between and are flattened by a pair of opposed milling and gripping rolls. During passage, the milling roll scrapes pith from one side of the stalk while the gripping roll controls the rate of stalk movement. This technique is described in detail, for example, in U.S. Pat. No. 3,567,510, referred to previously. It will be apparent that the methods and appartus disclosed therein have opened a new dimension in the art of sugarcane stalk processing in which effective stalk separation may be accomplished by means of high speed equipment which is capable of rapidly handling large quantities of stalk material.
Although the above-discussed separation methods and apparatus are capable of effectively processing a relatively heavy flow of rapidly moving stalk material, there remains room for improvements in efficiencies and techniques in various areas of operation.
For example, a chute which has been used for guiding a flow of stalk material to a separator unit includes a series of parallel guides or channels. The occurrence of varying concentrations of stalk material of random widths within a channel may tend to restrict the material flow, thereby resulting in an uneven flow rate, or may cause clogging of the channel, thus cutting off the flow of material to the separator.
In some instances, where the stalk material is being fed by the feed rolls against the splitting blade, there may develop some skewing and slippage of the stalks relative to the feed rolls. As a result, the efficiency, rate of production, and uniformity of results tend to be reduced.
In other cases where the separated rind components of the stalk material are to be fed to a shredding unit, it is preferable that they be longitudinally aligned for an effective shredding operation. Considerations of time and space dictate that a compact aligning apparatus capable of rapid and effective operation be provided.
The significance of other problem areas will be apparent upon considering that a shutdown of the apparatus for extended periods can result in a significant loss in production. Indeed, the time and effort involved in the performance of maintenance operations such as disassembling the separator apparatus for cleaning or replacing machine parts can be costly. Thus, it would be advantageous to develop methods and apparatus for reducing such time and effort, as well as avoiding or reducing the frequency of stalk jam-ups and other stalk and rind handling problems.